/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.tarena.manager.ui.viewpage;

import android.view.MotionEvent;

/**
 * Helper for accessing features in {@link MotionEvent} introduced after API
 * level 4 in a backwards compatible fashion.
 */
public class MotionEventCompat {
	/**
	 * Interface for the full API.
	 */
	interface MotionEventVersionImpl {
		public int findPointerIndex(MotionEvent event, int pointerId);

		public int getPointerId(MotionEvent event, int pointerIndex);

		public float getX(MotionEvent event, int pointerIndex);

		public float getY(MotionEvent event, int pointerIndex);
	}

	/**
	 * Interface implementation that doesn't use anything about v4 APIs.
	 */
	static class BaseMotionEventVersionImpl implements MotionEventVersionImpl {
		@Override
		public int findPointerIndex(MotionEvent event, int pointerId) {
			if (pointerId == 0) {
				// id 0 == index 0 and vice versa.
				return 0;
			}
			return -1;
		}

		@Override
		public int getPointerId(MotionEvent event, int pointerIndex) {
			if (pointerIndex == 0) {
				// index 0 == id 0 and vice versa.
				return 0;
			}
			throw new IndexOutOfBoundsException(
					"Pre-Eclair does not support multiple pointers");
		}

		@Override
		public float getX(MotionEvent event, int pointerIndex) {
			if (pointerIndex == 0) {
				return event.getX();
			}
			throw new IndexOutOfBoundsException(
					"Pre-Eclair does not support multiple pointers");
		}

		@Override
		public float getY(MotionEvent event, int pointerIndex) {
			if (pointerIndex == 0) {
				return event.getY();
			}
			throw new IndexOutOfBoundsException(
					"Pre-Eclair does not support multiple pointers");
		}
	}

	/**
	 * Interface implementation for devices with at least v11 APIs.
	 */
	static class EclairMotionEventVersionImpl implements MotionEventVersionImpl {
		@Override
		public int findPointerIndex(MotionEvent event, int pointerId) {
			return event.findPointerIndex(pointerId);

			// return MotionEventCompatEclair.findPointerIndex(event,
			// pointerId);
		}

		@Override
		public int getPointerId(MotionEvent event, int pointerIndex) {
			return event.getPointerId(pointerIndex);
			// return MotionEventCompatEclair.getPointerId(event, pointerIndex);
		}

		@Override
		public float getX(MotionEvent event, int pointerIndex) {
			return event.getX(pointerIndex);
			// return MotionEventCompatEclair.getX(event, pointerIndex);
		}

		@Override
		public float getY(MotionEvent event, int pointerIndex) {
			return event.getY(pointerIndex);
			// return MotionEventCompatEclair.getY(event, pointerIndex);
		}

	}

	/**
	 * Select the correct implementation to use for the current platform.
	 */
	static final MotionEventVersionImpl IMPL;
	static {
		IMPL = new EclairMotionEventVersionImpl();
//		if (android.os.Build.VERSION.SDK_INT >= 5) {
//		} else {
//			IMPL = new BaseMotionEventVersionImpl();
//		}
	}

	// -------------------------------------------------------------------

	/**
	 * Synonym for {@link MotionEvent#ACTION_MASK}.
	 */
	public static final int ACTION_MASK = 0xff;

	/**
	 * Synonym for {@link MotionEvent#ACTION_POINTER_DOWN}.
	 */
	public static final int ACTION_POINTER_DOWN = 5;

	/**
	 * Synonym for {@link MotionEvent#ACTION_POINTER_UP}.
	 */
	public static final int ACTION_POINTER_UP = 6;

	/**
	 * Synonym for {@link MotionEvent#ACTION_HOVER_MOVE}.
	 */
	public static final int ACTION_HOVER_MOVE = 7;

	/**
	 * Synonym for {@link MotionEvent#ACTION_SCROLL}.
	 */
	public static final int ACTION_SCROLL = 8;

	/**
	 * Synonym for {@link MotionEvent#ACTION_POINTER_INDEX_MASK}.
	 */
	public static final int ACTION_POINTER_INDEX_MASK = 0xff00;

	/**
	 * Synonym for {@link MotionEvent#ACTION_POINTER_INDEX_SHIFT}.
	 */
	public static final int ACTION_POINTER_INDEX_SHIFT = 8;

	/**
	 * Call {@link MotionEvent#getAction}, returning only the
	 * {@link #ACTION_MASK} portion.
	 */
	public static int getActionMasked(MotionEvent event) {
		return event.getAction() & ACTION_MASK;
	}

	/**
	 * Call {@link MotionEvent#getAction}, returning only the pointer index
	 * portion
	 */
	public static int getActionIndex(MotionEvent event) {
		return (event.getAction() & ACTION_POINTER_INDEX_MASK) >> ACTION_POINTER_INDEX_SHIFT;
	}

	/**
	 * Call {@link MotionEvent#findPointerIndex(int)}. If running on a pre-
	 * {@link android.os.Build.VERSION_CODES#ECLAIR} device, does nothing and
	 * returns -1.
	 */
	public static int findPointerIndex(MotionEvent event, int pointerId) {
		return IMPL.findPointerIndex(event, pointerId);
	}

	/**
	 * Call {@link MotionEvent#getPointerId(int)}. If running on a pre-
	 * {@link android.os.Build.VERSION_CODES#ECLAIR} device,
	 * {@link IndexOutOfBoundsException} is thrown.
	 */
	public static int getPointerId(MotionEvent event, int pointerIndex) {
		return IMPL.getPointerId(event, pointerIndex);
	}

	/**
	 * Call {@link MotionEvent#getX(int)}. If running on a pre-
	 * {@link android.os.Build.VERSION_CODES#ECLAIR} device,
	 * {@link IndexOutOfBoundsException} is thrown.
	 */
	public static float getX(MotionEvent event, int pointerIndex) {
		return IMPL.getX(event, pointerIndex);
	}

	/**
	 * Call {@link MotionEvent#getY(int)}. If running on a pre-
	 * {@link android.os.Build.VERSION_CODES#ECLAIR} device,
	 * {@link IndexOutOfBoundsException} is thrown.
	 */
	public static float getY(MotionEvent event, int pointerIndex) {
		return IMPL.getY(event, pointerIndex);
	}
}
